Diode-lasers provide a most efficient and compact means of light generation and are attractive as light-sources in many applications, particularly those in which light is required only in a limited range of wavelengths. Such applications include, for example, medical applications such as photodynamic therapy and depilation; machining, welding, and heat treating using light; providing pump-light-sources for solid state lasers; and simply providing illumination.
Diode-laser light-sources are frequently in the form of a "bar" which includes a plurality of individual lasers on a single semiconductor substrate. The lasers emit from the edge of the bar in a direction perpendicular to the length of the bar. Where one bar is insufficient to provide a desired power or brightness, an array of bars is used, one stacked above the other in a direction perpendicular to the emitting direction. Such an arrangement is usually referred to as a stacked bar array, or a two dimensional array of emitters.
The closer the bars are stacked, the brighter the array will be. Where the closely stacked bars are operated at high power or rapid pulse rates, however, problems are often encountered in removing heat generated during operation of the bars.
More or less effective solutions to the heat removal problem for such stacked bar arrays have been devised in the prior art. These solutions involve cooling arrangements which are often relatively complex compared with corresponding cooling arrangements for single diode-laser bar. Such arrangements may include complex mechanical assemblies, including cooling fins or microchannel plates. Because of this, the cost of a stacked diode-laser bar array can be increased significantly over the total cost of a comparable number of individual diode-laser bars.